MONTPELIER — It’s back to the trial court for a Vermont case in which a woman lent her car keys to a man who then gave them to the woman’s boyfriend, who then died in an accident.

The Vermont Supreme Court ruled Friday in the complex case in which the bottom-line question is whether the woman’s auto insurance should cover a lawsuit by the dead man’s family or the responsibility falls on the man who passed on the keys.

The family of the dead man, Kim Lamotte, is suing Seth Colby, who accepted the keys from Kelly Macie and gave them to Lamotte on a promise from Lamotte that he would not drive the car but just wanted to unload boxes from the trunk and listen to its radio.

The justices sent the matter back to the Superior Court for Essex County, saying a judge or jury would have to determine if it was reasonable for Colby to have believed Lamotte’s promise not to drive the car, or if Colby had engaged in “negligent entrustment.” If Colby acted reasonably, Macie’s insurance company, State Farm, would be liable for damages.

Here’s how the incident happened, according to the court’s ruling:

Colby picked Lamotte up hitchhiking in northeastern Vermont’s Essex County. Colby took him to a McDonald’s in Lancaster, N.H., where Macie, Lamotte’s girlfriend, worked. Lamotte asked Macie if he could borrow her car. Macie said no, because Lamotte had a lifetime driver’s license suspension for multiple drunken driving convictions and appeared to have been drinking at the time. Macie did give her keys to Colby, whom she didn’t know.

The decision did not explain why Macie gave Colby the keys when Colby’s truck was parked outside. Macie did not immediately return a call seeking comment, and a number for Colby could not be found.

“Somewhere between the counter where Macie gave Colby the keys and the car, Colby handed (Lamotte) the keys,” said the court decision written by Associate Justice Beth Robinson. “Colby told (Lamotte) not to drive the car, and (Lamotte) told Colby that he was not going to drive the car but was going to listen to the car radio. Colby then got in his truck and drove away.”

Colby saw Lamotte later that afternoon and told him he should not be driving. Lamotte got back in the car and, a short time later, drove it off the road.

Essex County State’s Attorney Vincent Illuzzi said Lamotte was decapitated by a utility pole’s support wire. Illuzzi said he investigated with an eye to bringing a criminal charge of accessory before the fact against Colby. But he said that because the passing of the keys occurred in New Hampshire, he did not feel he could bring the case in Vermont.